This invention relates to aquarium filters, and more particularly to aquarium filters of the type which can be placed at the bottom of the aquarium for filtration and aeration of contaminated water contained in the aquarium.
A common type of aquarium filter is generally referred to as the bottom aquarium filter. Such type of filters are positioned at the bottom of the tank, normally above the gravel bed. Such typical filters are shown in U.S. Pat. Nos. 2,782,161; 3,477,580; 3,630,367 and 4,186,093. The filters described in these, as well as various other bottom aquarium filters, all have various chambers defined for specified purposes. Specifically, there is typically defined a receiving chamber for receiving the contaminated water from the aquarium filter and passing it through filtration material. The water is then collected in a clear water chamber which is in flow communication within an air lift tube. A supply of air is provided to the bottom of the air lift tube and as the air drifts upwardly in the air lift tube it draws the water from the clear water chamber into the air lift tube to pass upwardly along with the air and then back into the aquarium tank in an aerated and filtered condition. The construction of the various prior art filters included well defined individually constructed compartments, each of which respectively served as one of the aforementioned chambers. When assembled, these compartments were joined to form the aquarium filter. In order to clean the filter, the various compartments had to be separated and individually cleaned. The cleaning of individual compartments caused difficulty since narrow brushes were often required to fit into crevices and corners of the various compartments and thereby inadequate cleaning often occurred.
An additional problem with the aforementioned prior art filters was the difficulty in manipulating these filters. Once assembled, the filter must be lowered into the aquarium tank and suitably positioned. In many cases, lowering the filter will cause it to be improperly situated in the tank and further manipulation of the filter assembly is required in order to properly position it at an appropriate location. Without externally available handles the aquarium owner's hands must be placed within the tank to reach the filter in order to properly position it. Similarly, insertion of the hands into the tank is required in order to extract the filter for cleaning. Such insertion of the hands often disturb the fish environment and may even contaminate the aquarium water causing damage to the various fish and plant life within the aquarium tank.
With most of the previous aquarium filters, the particular shape of the aquarium filter was rectangular so as to permit positioning of the aquarium filter in a corner of the aquarium tank. However, in doing so, narrow spaces were formed between the planar walls of the aquarium filter and the correspondingly planar walls of the filter tank. Such narrow spaces often provided insufficient room for the fish to swim therethrough and often fish could get caught and trapped between the walls of a square, rectangular or triangular shaped filter having flat sides with these sides confronting the aquarium tank walls.
Another construction problem with the prior art filters concerns the appropriate supply of air into the air lift chamber. Typically, a tube is inserted into the air lift chamber with an air diffuser or air stone, or the like, depending from the distal end of the tube. The air diffuser is usually placed at the lower portion of the air lift chamber and air supplied through the tubing is diffused through the air diffuser. Since the clear water chamber is usually adjacent or beneath the air lift chamber, the air passing from the air diffuser and flowing upwardly does not adequately pass by the clear water chamber itself and accordingly insufficient suction is provided by the air flow. Furthermore, the air flow does not have an opportunity to pass through the entire height of the air lift chamber since the air diffuser itself occupies a considerable portion of the height of the air lift chamber and air leaving from all parts of the air diffuser only has a portion of the height of the air lift chamber to travel through. Such short travel path provides insufficient aeration of the clear water passing back into the aquarium tank and also provides insufficient suction for adequate flow of water through the filter.
Accordingly, while the prior art bottom aquarium filters have been utilized quite successfully, further improvement is warranted in order to alleviate the aforementioned problems.